Contemplation of synchronous Gray Code counter and its variants using reversible logic gates

A Gray Code is an encoding of integers as sequences of bits with the property that the representations of adjacent integers differ in exactly one binary position. Gray Codes have many practical applications that go beyond research interests. There are different types of gray codes: Binary reflected, Maximum Gap, Balanced, Antipodal and Non Composite to name a few. On the other hand Reversible logic has received great attention due to their ability to reduce the power dissipation--an important aspect of low power circuit design. Other applications include Optical information processing, DNA computing, bio informatics, quantum computation and nanotechnology. Counters have a primary function of producing a specified output sequence and are thus sometimes referred to as pattern generators. This paper proposes design of different gray code counters using reversible logic gates, to draw comparative conclusions upon their performance.